1. Field of the Invention
This invention relates to medical devices and, more particularly, to arm slings and methods of supporting a patient's arm.
2. Prior Art
Previously, a variety of general-purpose arm slings have been available. These slings include those having a soft, very flexible envelope, or closed trough, which surrounds and provides some support to the patient's forearm. In some cases, slings of this design prevent easy access to the patient's arm for theraputic purposes. To provide support to the distal end of the patient's forearm, that is, the wrist and hand, this type of sling is supported by a strap attached near the distal end of the fabric envelope and extending around the patient's neck. The proximal portion of the supporting strap for a flexible envelope continues over or behind the shoulder of the arm being supported, that is, the ipsilateral shoulder. In such an arrangement the weight being supported often presses on the side or back of the neck of the individual. Moreover, the result is that the patient's arm extends across the front of the patients chest, rotation of the patient's upper arm at the shoulder joint is severely restricted, and elevation of the distal end of the patient's arm is difficult and uncomfortable. That is, if the strap is tightened to elevate the patient's hand and wrist, the arm is pulled even more tightly to the chest. The height of hand elevation is limited by how tightly the strap can be made around the neck, how closely the trough can be brought to the neck, and whether or not the distal end of the flexible envelope collapses in the process of elevation, thus allowing the hand and wrist to droop.
Examples of various types of arm slings having soft, flexible envelopes and/or prior methods of suspension, are disclosed in U.S. Pat. Nos. 980,464; 3,103,216; 3,433,221; 4,232,664; and 4,285,337.
Specific apparatus for rigidly fixing a patient's wrist and hand in position on a relatively rigid forearm supporting member are disclosed in U.S. Pat. Nos. 3,815,588 and 4,214,579, both of which apparatus include support straps extending over the patient's opposite, that is, contralateral, shoulder, which prevents rotation of the patient's upper arm at the shoulder joint.
A variety of arm sling positions are desired depending upon the patient's particular injury or disability; so that an arm sling which provides for a wide range of positions depending upon the needs of a particular patient is very desirable. These positions include one in which the upper arm is substantially vertical while the forearm is substantially horizontal and extends across the patient's lower chest. Another position is one in which the upper arm is still vertical but the forearm is elevated from the elbow at approximately 45 degrees and extends across the front of the patient's chest, keeping the patient's hand above the heart to prevent edema.
Some prior art slings include an elbow pocket to help support the arm and to keep the patient's arm in the fabric envelope when the forearm is elevated. Slings which have a soft, fabric envelope do not always adequately support the patient's hand and wrist, especially when the forearm is elevated, since the flexible envelope tends to telescope downward along the forearm. While others do provide support, they do so by rigidly holding the patient's hand in position with a strap. In some cases rigidly holding the hand may perhaps be necessary, but for other cases requiring support only, these slings may be very uncomfortable.